 <template>
 	<view class="u-wrap">
 		<view class="u-menu-wrap">
 			<scroll-view scroll-y scroll-with-animation class="u-tab-view menu-scroll-view" :scroll-top="scrollTop">
 				<view v-for="(item,index) in tabbar" :key="index" class="u-tab-item"
 					:class="[current==index ? 'u-tab-item-active' : '']" :data-current="index"
 					@tap.stop="swichMenu(index)">
 					<text class="u-line-1">{{item.categoryName}}</text>
 				</view>
 			</scroll-view>
 			<block v-for="(item,index) in tabbar" :key="index">
 				<scroll-view scroll-y class="right-box" v-if="current==index">
 					<view class="page-view">
 						<view class="class-item">
 							<view class="item-container">
 								<view class="thumb-box" v-for="(item1, index1) in item.goods" :key="index1">
 									<image @click="toDetails(item1)" class="item-menu-image" :src="item1.imageUrl.split(',')[0]" mode=""></image>
 									<view class="item-menu-name">{{item1.name}}</view>
 								</view>
 							</view>
 						</view>
 					</view>
 				</scroll-view>
 			</block>
 		</view>
 	</view>
 </template>

 <script setup scoped>
 	import {
 		ref,
 		getCurrentInstance
 	} from 'vue';
 	import {
 		getCategoryListApi
 	} from '../../api/category';
import { onLoad } from '@dcloudio/uni-app';
 	//获取组件实例
 	const instance = getCurrentInstance();
 	const tabbar = ref([ ])
 	const scrollTop = ref(0) //tab标题的滚动条位置
 	const current = ref(0) // 预设当前项的值
 	const menuHeight = ref(0) // 左边菜单的高度
 	const menuItemHeight = ref(0) // 左边菜单item的高度
 	const getImg = () => {
 		return Math.floor(Math.random() * 35);
 	}
 	// 点击左边的栏目切换
 	const swichMenu = async (index) => {
 		if (index == current.value) return;
 		current.value = index;
 		// 如果为0，意味着尚未初始化
 		if (menuHeight.value == 0 || menuItemHeight.value == 0) {
 			await getElRect('menu-scroll-view', 'menuHeight');
 			await getElRect('u-tab-item', 'menuItemHeight');
 		}
 		// 将菜单菜单活动item垂直居中
 		scrollTop.value = index * menuItemHeight.value + menuItemHeight.value / 2 - menuHeight.value / 2;
 	}
 	// 获取一个目标元素的高度
 	const getElRect = (elClass, dataVal) => {
 		new Promise((resolve, reject) => {
 			const query = uni.createSelectorQuery().in(instance);
 			query.select('.' + elClass).fields({
 				size: true
 			}, res => {
 				// 如果节点尚未生成，res值为null，循环调用执行
 				if (!res) {
 					setTimeout(() => {
 						this.getElRect(elClass);
 					}, 10);
 					return;
 				}
 				instance[dataVal] = res.height;
 			}).exec();
 		})
 	}
 	//获取分类数据
 	const getCategoryList = async () => {
 		let res = await getCategoryListApi()
		if(res&&res.code==200){
			tabbar.value=res.data;
		}
 	}
	//跳转详情
	const toDetails = (item) => {
		uni.navigateTo({
			url: '../detail/detail?goods=' + encodeURIComponent(JSON.stringify(item))
		});
	}
	onLoad(()=>{
		getCategoryList()
	})

 </script>

 <style lang="scss">
 	.u-wrap {
 		height: calc(100vh);
 		/* #ifdef H5 */
 		height: calc(100vh - var(--window-top));
 		/* #endif */
 		display: flex;
 		flex-direction: column;
 	}

 	.u-search-box {
 		padding: 18rpx 30rpx;
 	}

 	.u-menu-wrap {
 		flex: 1;
 		display: flex;
 		overflow: hidden;
 	}

 	.u-search-inner {
 		background-color: rgb(234, 234, 234);
 		border-radius: 100rpx;
 		display: flex;
 		align-items: center;
 		padding: 10rpx 16rpx;
 	}

 	.u-search-text {
 		font-size: 26rpx;
 		color: $u-tips-color;
 		margin-left: 10rpx;
 	}

 	.u-tab-view {
 		width: 200rpx;
 		height: 100%;
 	}

 	.u-tab-item {
 		height: 110rpx;
 		background: #f6f6f6;
 		box-sizing: border-box;
 		display: flex;
 		align-items: center;
 		justify-content: center;
 		font-size: 26rpx;
 		color: #444;
 		font-weight: 400;
 		line-height: 1;
 	}

 	.u-tab-item-active {
 		position: relative;
 		color: #000;
 		font-size: 30rpx;
 		font-weight: 600;
 		background: #fff;
 	}

 	.u-tab-item-active::before {
 		content: "";
 		position: absolute;
 		border-left: 4px solid #F3AF28;
 		height: 32rpx;
 		left: 0;
 		top: 39rpx;
 	}

 	.u-tab-view {
 		height: 100%;
 	}

 	.right-box {
 		background-color: rgb(250, 250, 250);
 	}

 	.page-view {
 		padding: 16rpx;
 	}

 	.class-item {
 		margin-bottom: 30rpx;
 		background-color: #fff;
 		padding: 16rpx;
 		border-radius: 8rpx;
 	}

 	.item-title {
 		font-size: 26rpx;
 		color: $u-main-color;
 		font-weight: bold;
 	}

 	.item-menu-name {
 		font-weight: normal;
 		font-size: 24rpx;
 		color: $u-main-color;
 	}

 	.item-container {
 		display: flex;
 		flex-wrap: wrap;
 	}

 	.thumb-box {
 		width: 33.333333%;
 		display: flex;
 		align-items: center;
 		justify-content: center;
 		flex-direction: column;
 		margin-top: 20rpx;
 	}

 	.item-menu-image {
 		width: 120rpx;
 		height: 120rpx;
 	}
 </style>